Many food and beverage products include chemical preservatives to extend the shelf-life of the product by inhibiting the growth of spoilage microorganisms (e.g., mold, yeast, bacteria). However, some preservatives currently in use have been characterized as either a detriment to one's health, a threat to the environment, or as insufficiently stable. Therefore, there is market demand for food and beverage products which do not include these detrimental preservatives, and yet still possess extended shelf-life.
For example, benzoic acid and its salts are commonly used in beverage products as preservatives. However, in some beverage formulations that possess vitamin C and a relatively high pH, a small fraction of benzoic acid and its salts is prone to conversion into benzene (ppb quantities). Heat and certain wavelengths of light increase the rate of this reaction, so extra care need be taken in the production and storage of beverage such products when both benzoate and ascorbic acid are ingredients. Intake of benzene in drinking water is a public health concern, and the World Health Organization (WHO) and several governing bodies within the United States and the European Union have set upper limits for benzene content in drinking water of 10 ppb, 5 ppb, and 1 ppb, respectively.
Ethylenediamine tetraacetic acid (EDTA) and its salts are also common beverage product preservative. EDTA sequesters metal ions and can impact their participation in any number of chemical reactions. At elevated concentrations, EDTA can serve to starve bacteria of needed trace elements. At relatively low concentrations as typically found in beverage, EDTA facilitates the activity of at least weak acid preservatives such as sorbic and benzoic acid. However, EDTA is not bio-degradable, nor is it removed during conventional wastewater treatment. EDTA has surfaced as environmental concerns predominantly because of its persistence and strong metal chelating properties. Widespread use of EDTA and its slow removal under many environmental conditions have led to its status as the most abundant anthropogenic compound in many European surface waters. River concentrations of EDTA in Europe are reported in the range of 10-100 μg/L, and lake concentrations of EDTA are in the range of 1-10 μg/L. EDTA concentrations in U.S. groundwater receiving wastewater effluent discharge have been reported in the range of 1-72 μg/L, and EDTA was found to be an effected tracer for effluent, with higher concentrations of EDTA corresponding to a greater percentage of reclaimed water in drinking water production wells.
Polyphosphates are another type of sequestrant employed as a beverage product preservative. However, polyphosphates are not stabile in aqueous solution and degrade rapidly at ambient temperature. Degradation of polyphosphates results in unsatisfactory sensory issues in the beverage product, such as change in acidity. Also, the shelf-life of the beverage product can be compromised as the concentration of polyphosphate deteriorates.
It is therefore an object of the present invention to provide new preservative systems for use in beverages as replacements for at least one currently used preservative that has detrimental health and/or environmental effects, or lack of sufficient stability. It is further an object of the invention to provide new beverage preservative systems with improved sensory impact. It is further an object of the invention to provide preservative systems without benzoic acid and/or reduced concentrations of sorbic acid. Some countries have regulatory restrictions on the use of sorbic acid in food and beverage products wherein the permitted concentration is less than is required to inhibit the growth of spoilage microorganisms.